Conventionally, when transporting instruments which are easily damaged by tilting and falling, for example precision instruments such as hard disks, an object tilt and fall detection apparatus for detecting the tilt and fall of an object is disposed on a box body (object) in which a large number of the precision instruments is stored.
An example of this type of object tilt and fall detection apparatus is described in U.S. Pat. No. RE 32570.
FIG. 21 is a schematic perspective view showing a conventional object tilt and fall detection apparatus 1 disposed on a box body 2 (object) in which a large number of precision instruments such as hard disks is stored.
Note that in FIG. 21, the object tilt and fall detection apparatuses 1 are disposed respectively on each side face of the box body 2 in consideration of the tilting or falling direction of the box body 2.
As shown in the front view of FIG. 22 and the schematic A-A sectional view of FIG. 23, this conventional object tilt and fall detection apparatus (to be referred to simply as “detection apparatus” hereafter) comprises a main body 3 having a rectangular front face and formed with a recessed portion 4 having a C-shaped cross section, and a lid body 5 for covering the recessed portion 4 of the C-shaped cross section from the rear face. Adhering means 6 such as double-sided adhesive tape, for adhering the detection apparatuses 1 to each side face of the box body 2 in FIG. 21, are provided on the rear face of the lid body 5 and a flange portion 3a of the main body 3.
Note that both the main body 3 and lid body 5 described above are formed from a synthetic resin such as plastic.
As shown in FIG. 24, which is a cross section taken on a line B-B in FIG. 23, tilt detection means 10 for detecting a tilted state of the main body 3 are disposed inside the recessed portion 4 of the main body 3.
The tilt detection means 10 are constituted by a disk body 11 which rolls in accordance with the tilted state of the main body 3, and a guide member 12 for guiding the disk body 11.
The guide member 12 comprises a reference guide 13 which supports the disk body 11 from below when the disk body 11 is in its initial position, a pair of tilt guides 14, 15 for guiding the rolling motion of the disk body 11 when the main body 3 tilts to the left or right, and a restriction guide 16 which prevents the disk body 11 from moving a fixed distance or more.
Discharge ports 17, 18 through which the disk body 11 may roll are formed between the restriction guide 16 and respective tip ends 14a, 15a of the pair of tilt guides 14, 15.
The disk body 11 is formed from a metal plate, and each of the guides 13, 14, 15, 16 comprises a rib formed integrally with the main body 3.
Note that in FIG. 24, the reference numeral 20 denotes a circular transparent part formed in the main body 3. This transparent part 20 is formed so that the existence of the disk body 11 in its initial position can be confirmed easily from the front face of the main body 3 shown in FIG. 22.
According to this conventional detection apparatus 1, when the box body 2 shown in FIG. 21 tilts or falls such that the main body 3 of the detection apparatus 1 adhered to the box body 2 tilts in the direction of the arrow C, as shown in FIG. 25, the disk body 11 rolls along the tilt guide 14 from its initial position shown in FIG. 24, passes through the discharge port 17 between the tilt guide 14 and restriction guide 16, and falls downward, as shown in FIG. 25.
When the disk body 11 falls through the discharge port 17 of the restriction member 12 in this manner, the disk body 11 moves to a position in which it cannot be seen through the transparent part 20 of the main body 3.
Even when the fallen box body 2 is subsequently returned to its initial position shown in FIG. 21 such that the main body 3 of the detection apparatus 1 is returned to its initial position shown in FIG. 26, the disk body 11 does not return to its initial position restricted between the reference guide 13 and the pair of tilt guides 14, 15, and hence the disk body 11 cannot be seen through the transparent part 20.
Hence, even when the box body 2 is returned to its original position after falling over, an operator cannot confirm the existence of the disk body 11 by looking through the transparent part 20 of the detection apparatus 1, and it is therefore possible to definitely confirm that the box body 2 has fallen or tilted once.
Incidentally, with the conventional object tilt and fall detection apparatus 1 described above, it is possible for the operator to confirm that the box body 2 has not fallen or tilted by confirming the presence of the disk body 11 through the transparent part 20 of the main body 3. If the presence of the disk body 11 cannot be confirmed, the fact that the box body 2 has fallen or tilted once may be acknowledged.
However, with the conventional object tilt and fall detection apparatus 1 described above, although it is possible to confirm that the box body 2 has fallen, it is impossible to confirm the time at which the box body 2 falls.
As a result, if the object falls during transportation, for example, it is impossible to specify the stage of the transportation process at which the falling incident occurs, or in other words the approximate time at which the falling incident occurs.